SOLID AND POROUS TILE. 739 



■flows through this soil carries with it its atom of filth, caus- 

 ing fevers and death. Therefore, deep drains should be made 

 between the well and all places of filth. As the matter is 

 one of great importance, involving doctors' bills, sickness, 

 and death, it should have careful attention. 



ITS SINGLE DISADVANTAGE. 



Perhaps it is only fair to mention one disadvantage that 

 comes from drainage. If a swampy piece of woodland is sud- 

 denly drained, most of the old timber will die ; the oaks and 

 hickorys will go first. The change is first noticed in the tops 

 of the trees. However, the young timber soon accommodates 

 itself to the change, and after a time grows more thriftily than 

 ever. 



VELOCITY OF WATER IN TILE DRAINS. 



From the many experiments that I have made to ascertain 

 as nearly as possible the velocity of water in tile drains, I find 

 that in a six-inch tile, with a fall of four inches to the hundred 

 feet, when the tile was running full of water, it was eight rods 

 per minute, when running half-full, six rods per minute, and 

 the less v/ater there was in the tile the slower it would run. 

 The velocity of a twelve-inch tile when running full would be 

 swifter than this, while in the smaller sizes it would not be so 

 swift, and in an open ditch of the same fall the velocity is four 

 times less than that of a tile drain. 



SOLID AND POROUS TILE. 



I do not see any advantage in using porous tile. Solid tile 

 is stronger in all respects, and will not burst" and crumble like 

 porous tile from wet and freezing. If porous tile is full of 

 water and freezes, it is sure to expand and break and crumble. 

 Some say that tile should be porous so as to let the water 

 into the drain. If there were no other places for the water to 

 enter the drain except by the pores, the land would be poorly 

 drained. Now, for example, take any sized tile you please, 

 having the sixteenth of an inch at every joint (the space at the 

 joints is really greater than this), and, count it up for thirty 

 rods, you find that the water can get in at the joints many times 



